The present invention relates to a liquid atomizer device.
Such a liquid atomizer device is known from EP-A1-540774. The liquid atomizer device for producing an aerosol is especially used for inhalation purposes. Such devices must be sterilized after use. One possibility of sterilization is steam sterilization during which, however, the problem arises that the service life of the steam-sterilizable devices is limited. There is consequently the risk that the devices will fail during use after repeated sterilization. Disadvantageous consequences thereof might e.g. be the breaking of functionally essential parts, possibly resulting in a failure of the liquid atomizer device.
To solve said problem, DE 4311846 C1 discloses a service life indicator for repeatedly sterilizable plastic products which contains a color pigment that intermolecularly diffuses into the polymer material of the indicator in dependence upon the temperature. Since the diffusible pigment deeply penetrates into the polymer, it cannot be removed or impaired by cleaning processes performed on the surface. The display in the life indicator known from DE 4311846 C1 is such that during every steam sterilization the pigment will slightly diffuse to a further degree when pigment and polymer are correctly adjusted to each other. This has the effect that with each sterilization the pigment becomes paler, first in an unnoticeable and then in a noticeable manner. When polymer and pigment are suitably adjusted, the pigmentation will disappear after about hundred sterilization processes.
Despite the fact that said service life indicator has been known, its use in liquid atomizer devices has so far not been taken into consideration because in liquid atomizer devices the material of the device may be influenced not only by the sterilization but also by the liquid to be atomized and by the gas, in particular air, which is required for the atomization. Furthermore, the use of the known service life indicator in liquid atomizer devices has not been taken into consideration because the flow conditions in such devices are very complicated to ensure an optimum atomization. Therefore, it has been assumed that the mounting of the indicator would have a negative effect on the flow conditions and thus on the aerosol formation.
It is therefore the object of the present invention to provide a liquid atomizer device comprising a service life indicator that is used to avoid a premature disposal, but does not affect the aerosol formation.
Since the service life indicator is mounted at a place that does not impede the passage of the flow, but which may come into contact with both the aerosol to be produced and the sterilant, this has the effect that influences that might be exerted by the aerosol to be formed on the material of the liquid atomizer device of the invention and also by the sterilant are sensed by the service life indicator and thus can be indicated. Investigations conducted within the scope of the invention have shown that for the first time it has been possible by virtue of this special mounting to successfully use the service life indicator, which is per se known, in a liquid atomizer device for producing aerosols.
In a preferred embodiment of the liquid atomizer device according to the invention, the service life indicator is arranged in the housing so that it is protected against damage caused by externally acting forces, e.g. when the device is handled.
To fasten the service life indicator in an easy manner, the service life indicator may be mounted on a nebulizing chamber divider. In the disassembled state of the liquid atomizer device said nebulizing chamber divider is easily accessible and clearly visible, so that the service life indicator immediately will be perceived by the operator.
Furthermore, the service life indicator preferably is mounted either at the bottom side of a baffle section or at the upper side of the baffle section of the nebulizing chamber divider. As a result, the mounting of the service life indicator is further simplified and the indicator can be perceived clearly at the same time.
In a further preferred embodiment of the present invention the service life indicator is designed as a portion of a first housing part or of a second housing part. An additional component in the form of a separate service life indicator is thus not necessary so that the assembly of the liquid atomizer device of the invention is simplified. Nor is there any risk that the service life indicator is unintentionally separated or gets detached from the liquid atomizer device of the invention, so that during further use of the liquid atomizer device an indication of the service life is no longer given.
To prevent any unintentional detachment of the service life indicator from the liquid atomizer device, the service life indicator is integrally connected to the portion of the first holding part and/or of the second housing part.
In an alternative embodiment the handle of the liquid atomizer device comprises a service life indicator positioned within the housing. It is thereby possible to first secure the service life indicator to the end of the handle which faces the housing of the liquid atomizer device and then to insert and secure the handle into and to the housing so that the service life indicator is again arranged at a place accessible to the aerosol and the sterilant.
To counteract the effect of the flow passing through the device when the service life indicator is formed on the handle, the service life indicator may be provided with a flow guiding surface. This flow guiding surface permits an optimum guidance of the flow within the liquid atomizer device towards the suction nozzle of the liquid atomizer device.
Finally, to avoid an operation in which the service life indicator is mounted on the handle, the service life indicator may be made integral with the handle.